Ukraine's National Security and Defence Council spokesman Andriy Lysenko said international investigators believed data from the flight recorders show "the reason for the destruction and crash of the plane was massive explosive decompression arising from multiple shrapnel perforations from a rocket explosion".

Surface-to-air missiles such as the Buk system widely believed to have shot the passenger jet down can explode near their targets, blasting a cloud of shrapnel into them.

Investigators leading the probe in the Netherlands, which lost 193 citizens in the air disaster, refused to confirm the latest information from Kiev, saying that they were "waiting to get a more complete idea of what happened".

Kiev and its Western allies, including Australia, have accused insurgents of shooting down the plane, killing all 298 people on board, including 38 Australian citizens and residents.

Bishop hopeful of agreement to allow armed AFP officers on site

Foreign Minister Julie Bishop is in Kiev where she was due to hold talks with Ukraine's president Petro Poroshenko.

Ms Bishop is hopeful Ukrainian MPs will ratify an agreement to allow AFP officers in Ukraine to carry weapons onto the site.

She says the AFP mission will remain unarmed, but wants approval for weapons to be carried as a contingency plan.

"Part of that is to have the right, should it ever be necessary, to bring arms into the country for self-defence," Ms Bishop said.

"Now, I don't envisage that we will ever resort to that, but it is a contingency planning, and you would be reckless not to include it in this kind of agreement.

"But I stress our mission is unarmed because it is [a] humanitarian mission."

The Foreign Minsiter's comments came after the United Nations said the downing of Malaysia Airlines flight MH17 "may amount to a war crime".

UN High Commissioner for Human Rights Navi Pillay condemned the "horrendous shooting down" of the passenger jet and demanded a "thorough, effective, independent and impartial investigation".

Earlier, On the ABC's 7.30 program, Ms Bishop was asked if there would be a criminal investigation into whether Russia armed and trained the rebels believed to have shot the plane down.

She said those responsible would be held to account.

"We think it is very important that the families of those killed have answers, and we believe it is important that those who are responsible for this, those culpable for this act, are brought to justice," Ms Bishop said.

"After all, this was a commercial airline in commercial air space that was shot down, we believe, by a surface-to-air missile.

"And those who created the conditions to enable in to happen should account for it."